The Adventures of an Ordinary Man at Making Things

Monthly Archives: October 2012

My ’01 Clio leaked liquid to the floor. Closer inspection showed that cabin heater radiator had some problems. I decided to replace it. I ordered the replacement part from local shop and after it arrived it was time to get hands dirty. The whole thing took from me about 4 hours.

This is from the early stage.

Since cabin heater radiator is deep inside the car, a whole lot of things had to got out. Steering wheel, dashboard, passenger’s airbag, temperature and air flow controllers, etc.. I had to even loosen those iron bars to get radiator out..

After a bit disassembling we have a cause of our problems in our hands. The white thing shows that this really is our bad guy.

To make really sure, here is the bad boy itself.

Shiny new one:

New and old one for matching..

And all back together:

Further inspection showed that no leakage was found. Job well done!

After repairing it was time to see what was inside the broken one: Plastic heads, thin lamels, some piping and spirals that make coolant liquid really spin inside the piping.

Disclaimer: If you make something similar showed in this blog and you or somebody or something gets hurt I am not responsible for that. Do it at your own risk.

As we all N900 owners know, battery life of the phone is not very good. After three years I finally got tired of sticking charger cable in every night to the phone and started to think how charging could be done differently. Few days went by and then I remembered: A while ago I saw in a supermarket a wireless charging kit for Nintendo Dsi. Could that kit be the key for N900 wireless charging?

I quickly googled the DSi battery and closer inspection showed that the battery voltage was the same in both devices, 3,7V. In the original DSi charging system there is a some kind of system that tells to the loading station when stop charging. (I guess system measures charging current or voltage and when certain level is achieved charging is stopped.) If I use DSi battery’s electronics I should be safe, the only thing that changes in the system is battery capacity. Also N900’s battery has its own protection system from overcharging so there is actually a double safety option. Feeding power back to N900 is another story but I think it can stand it.

Off to the supermarket we go.. Kit was still there and I quickly bought it. 15€ well spent.

Package:

Battery:

One can see that the charging system uses only two wires, positive and negative. Third terminal of the battery is not used at all. That makes things easier, right?

I quickly disassembled the station. Manufacturer seems to added some weight to get more solid feel to it..

N900’s battery BL-5J. There are two small screws in the plastic head, covered with plastic, you have to do some digging. Also sticker pads needs to be removed before head comes out.

Some wires soldered. Be careful when soldering a Li-Ion battery terminals!

Fitting things together. On the right there is the coil and electronics from DSi’s battery. They are connected by two wire to the BL-5J battery positive and negative terminals.

First tests show that system is working and don’t get heated generally at all. Still, more testing needs to be done. It looks like charging is a bit slow, due the double electronics safety mechanism in the BL-5J and in the wireless charging system. (Maybe I should get more involved with some measurement equipments? :))

Because charging happens directly from battery’s terminals, N900 don’t look like charging, battery graph don’t do that rising thing what it normally do when charging. This should keep in mind, I don’t advise you to put any cables to N900’s micro USB port while this system is connected to you N900.. Maybe there should be a slide switch which disconnect the wireless charging electronics from the phone.

Also station is very picky about the position of the phone on top of it.

If I can get system reliable enough I might try to make some cover for coil’s electronics. This is a spare phone so I don’t have to carry it around and thus there is no hurry. In todo-list there is also a proper power feed for station, right now I feed the thing from PC’s USB port.

Last spring I bought a 1999 BMW. The Driver’s side seat heater was broken and where I live winters can be pretty cold and snowy. With no other option than repair the thing I started to work.

On the first picture can be seen some bars and rings that hold the linings on the cushion. It was a nightmare to get all 18 (or was them 16?) rings off. And later back on, too 🙂

On the second one is the heater element itself. Element had no damage but the wires feeding it had. Both of them were broken. I added some new wires and measured that everything was ok. Then I put the lining back on the cushion with those small rings and put seat back together. Cushion is held in place with 4 small black plastic pins which tend to brake when taking cushion off from the seat, so you need to have them spare before starting to work..